1. Field of the Invention
This invention relates generally to the field of ski bindings and more particularly concerns the field of cross country ski bindings of the toe binding type.
2. Description of the Prior Art
Typically, cross country ski bindings of the toe binding type comprise a toe iron anchored to the ski, in which a resilient clamping member generally constructed of sturdy wire is mounted. When the toe of a cross country ski boot is placed in the toe iron, an extending portion of the boot sole is slipped under the clamping wire. The typical toe binding also includes means for pressing the clamping wire down on the extending sole portion and holding the clamping wire down on the boot sole. Such typical cross country ski bindings are disclosed in the patent to With, U.S. Pat. No. 3,481,618, and the patent to Kjellstrom, U.S. Pat. No. 3,905,612.
The motion utilized in cross country skiing or ski touring requires that the heel of the cross country ski boot be lifted regularly from the ski. The typical cross country toe binding, of which the With and Kjellstrom bindings are representative, make no provision for this heel lifting action, relying instead upon the flexibility and resiliency of the boot sole to effect such action. Such a system presents several problems. For example, the constant upward pressure exerted by the boot sole against the downward pressure of the clamping wire, in combination with the constant flexing of the boot sole as the heel is lifted, tends to loosen the boot sole in the toe binding. Also, great stress is placed on the boot sole by its constant flexing, which impairs its useful life. Finally, and most importantly, the flexibility of the boot sole with such bindings is necessarily limited, which impairs the ability of the skier to perform serveral maneuvers which may be required of him.
Several cross country toe bindings have recognized these problems, and have provided a hinging action at the toe piece. Two such bindings are disclosed in West German Pat. No. 2,333,042, issued Apr. 4, 1974, and West German Pat. No. 2,127,935, issued Dec. 16, 1971.
The toe bindings providing for hinging movement relative to the ski, which have been heretofore known, have left several problems unsolved. For instance, such toe bindings have commonly contained separate hinging mechanisms, clamping bars, and means for holding the clamping bars secure on the boot sole. With such a number of parts, the bindings present the problem of higher costs to manufacture. Furthermore, the heretofore known hinging toe bindings have been constructed so that the upward pressure exerted against the clamping bar by the boot sole has tended to move the clamping bar in such a way as to release it from the holding means clamping it down on the boot sole.